SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'eb3877757317fc1a4e71e2c43017c38242a49cbdaf277ad9186f18399fdf32db' 
  AND token = 'WZdFIiT8as3oDAWlZpJN8Ipn8Mfi17/H28mhvX7uqWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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