SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98dc19fc68b3a36576550275434a545f6b8a18335ad7b7d006b6035843e396ec' 
  AND token = 'AUJsKDhlerTWVtvjKBgXSokSoknYciG8Ec7nbtgIee4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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