SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '12c814bc489283230a9fae9729eb5cb36f7db504057a623ae88489f49c3b6512' 
  AND token = 'IrHgjwEe5zStz5r7DV5YnDxncSP+uVwEyNzJvANeg5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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