SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f325d7eafb8ce5f7728d9862d6add1a02d63a64bc73abfa19b49f534a11d677' 
  AND token = '+rEVchEQF/3+0aP1iShIjc1p7hV+NGJNDYmqBBASn9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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