SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efcce78c6f671e687e98ebd112938e5d195777b485374bec18e30bd6996ac131' 
  AND token = 's10EUrKzH8n6WrtDdaD5S0+3eUOW6DJNmQtHUKTxxAI=' 
  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"
    }
  }
}