SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1239e119f6b461a58639399b03aa41bd213051339d4e490311584357ba93cbde' 
  AND token = 'crp5gkRg+vG7DwqXCdEVvAKxRFMDDDtwmoVgZ08CTiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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