SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a249d41eaa8bd097e3dbd30150b58b5128fcbb74c898af1238e3cb96b072633c' 
  AND token = 'oDyOpy66suQTE/dzneMR0DSjjZ6UuFOfi0QENMOXmyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}