SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a74193f276add08be536a3b71e52cd738db809c9896ffa9fa30b776e46fc582' 
  AND token = 'yAtAefdtXp0fveiH/MvUyzm1y27QFo5v5UQhRnpMQOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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