SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '355741980604a64b75dc40c7d1885ee1cdf53bfe6d87895d37faab79c79e7468' 
  AND token = 'AcdMeUgRo8V8eFnLLmli+RK8+7MEXsXNHWeC0hozxhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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