SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d0545a033954bd211895ee86e68f66d732b5b58c4c0b55d935402d6713303c6' 
  AND token = 'qPwPPj5ZOlwtiAxtbxYEHlVmByob289uPSt4XDLYHns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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