SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '381809c34d12319ff1f59e3acf66f31764d3b4b1cd5c237da79477b6d2d22d57' 
  AND token = 'QiCB57F1fRj1PRhnzmNy4/NRQPF6TtKzdmomsxaWY2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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