SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98c542032b11009f5d0949563beb93db582961e7608f88fcabe1c5bcc5eb2dd2' 
  AND token = 'X2EmiT2XRMtnmTt1XbsxZakqPArYZO+tsrmjPapzoaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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