SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '992c81042922e9186d6046806b75cccd0816dc8ed3482d831db9638172e38673' 
  AND token = 'C7f7qLif2KTGnDvG1cKp6JoM9rMY1Z5L/m+3LxA4yZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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