SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8779a7aabfa466423128ee912ee29cb63bbc9b3b15368acf4d462dd47c438f1e' 
  AND token = '1wMLcVCqtgiMxi6U7y2XROQ50bvn/PKr4jwlUh/8vBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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