SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfdf61b8619d80a841ffdc8b997876a1110336ba19073ce55d198a25cd71c60a' 
  AND token = 'abFhDjGVu2leHhQTBVmt053LKgVexJnbZ4oxwn6QC+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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