SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ad2b196a791d6cc71c01785573e3e2309e5b5717afe47d9379a5c1aa0e5c5c5' 
  AND token = 'nIzDwBCo+qcVLN3cqomuB4vugkGGS54YPnE5+lyYKds=' 
  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"
    }
  }
}