SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a65c0079bdaaabff3a1e637616ac2af4bf45a3c81d69a6085be0786d9bfaac46' 
  AND token = 'qscxxrOKbfXk3kfhV2iu+qNMn4I7zFO4LNTVtwty5bk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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