SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f985927cca62f8aa775555b5c1727c9c0e7329c31b4de8829937fd6ea85b2dd' 
  AND token = 'K1RCmAWKEGuFE3H7ep0V1zsdSrkuB5HMCmcFkFaTd0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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