SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '007619d250cc2783e10fa1fa8c21b16316638f9b0a3fd2ff4c0827e228e4311b' 
  AND token = 'bNFRNDMWkSQGDFBnh3ithLpkxCRdQfypBAa4blc2388=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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