SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5417708fcb1f5773837bfecac330d50c95e27ec1dd7cd347e9daf240fc0da981' 
  AND token = 'HCl+jVd7yJ0ZsPdHLsvsabuGg8koUdq8yxDmZjmMriY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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