SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc389b4f6a835b98cbec81d1e1bfa694b346a4587422a00507c57435e921e5f6' 
  AND token = 'vPRujXeGJ5vgzraIETbQUpU44WfYGby2yO05aqofsEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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