SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd49619171636bb58c6eab088f68102c7fcfb697ef9a383bccc990dd78cf3bd8' 
  AND token = 'hWorw+VQWkuTMZvxEFN4g6BqyEVqjj0GO9Ez+T01X94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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