SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c89998eaa0f86f86931f5f6d6bdd6dd87031481f93189ac2997ec145d4f6b9ac' 
  AND token = '8Pf+3KxhM7xScTIoEqCkDxe4dL1vdEJdkMXo8NdSo0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}