SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd815414b1f5e1cd9316f2cf9749c02632c52c83dd4aa7717921955bcfd646a92' 
  AND token = 'RfcYgG1oHyYF7U+pSeXSY26bFLRsZqqmPkoynDyr9uw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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