SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b9d0bb5af56c33c392ddff36559f04aebc7bcffeeb1bc93806376a2c5a3aa41' 
  AND token = 'livonvzBGVzxys1hHZlmQ+DyCWp8emSvgA3V2xf7GJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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