SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d314f45e91b9f49c6de42ff653834087fe740f8a7dfafc2f072260a74fa741d' 
  AND token = 'tqiYWSgLJ1cu+QDHBPHPQKxX8wRJcMVXSlGePU0FuQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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