SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af89f407f76e72a80431a5155299ce4371d2a2dab3e3f1f970d9ced787b9b6a3' 
  AND token = 'Bf5zc3kvxTDmUVrAjp+goRj5lgVaCXtBHMKHpPdQcT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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