SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31fa54f6cb4772054d98df5237e5bbec444964e56070042156cff0c63b0f5374' 
  AND token = 'S02iYVgNnMNUNJkvbYe0tSp7Me8e9R1wq1Lc9a3dvjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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