SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cca59921757c627f356b34543eaa30f336ddbc83017034ede1f7378d1627b207' 
  AND token = 'KFXd79Rr8PrnoFZkJdRn3Q3IC+GkhUcnVqCLVioHz+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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