SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '471c05f9a1ef756f00afda15eb43ab21527c36307301412450c0a803228b26c5' 
  AND token = 'hdervXX6PPg18znpC+eEYUJLF9Mw/BIC+YotPmz7KfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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