SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '890401f8855553ec1246089579d7a71633fd1a5f4e456a9020ea86a7e8f5c597' 
  AND token = 'GJcw/5mc1daIEJ7+q+P2qijPYsguBHpaBi4zQObw7Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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