SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b33cb0a8c4d35b8e07c34477adc439a2798cf9e18d8ccf114f8ffe79209f78b6' 
  AND token = 'Eq+DE3pf/IV/qDaXHpkcijDtr20msgDBNPacvvKzp5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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