SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56c7f6c0f66e7ef7bb23e044d57225b2beb7e0da0331621f7829a0b8da15cd4c' 
  AND token = 'zuyP3xzT0zgGyOPcVn/IYMxgKARZDufJ4YVOgmqoRnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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