SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a711e1fb24cbb3687f0bf025a0a2d2496760236fc58e3d3e9031a5d9f5e60d14' 
  AND token = 'VY/TPqj/+Kau/SPFpoD3y+TPDYDWHsGwwKIMaPL+HJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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