SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f16bd1e6612cc928b75baa66b6b5323ee87f263dc0b72700c3d16b007652088' 
  AND token = 'KGDM4q7KVBzxVvMoCsTztLYwfPBIfPrGgmgMlLo3V0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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