SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66943c3d19b375793604e9cafadb62d1e28063111b5439e6155c99dcc1bac1a8' 
  AND token = 'QwzGf3JWs2SHD1eW9Npi1IRSfUicN/Xt1l/07Aq7gU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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