SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f20170082e3512c15d2e3fba6e68db8e4a207aba5aa63eb2c3b93f599897a689' 
  AND token = 'sEePkLx0eZIooGiMVAidsYLt0tcrrRtioIqdZuK8XhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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