SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6caed73e0572a0e5120066891179af9d872e2aecca3797f8f19963d2bc4a7f3' 
  AND token = 'fRUzVDN8kWFS5ZR3kK/Ruk69WkkRsI4gIlY9Fu/1gfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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