SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8aaf18c701007a6c059f388c31dc5715bad8bf528acb517e6d4810a86f584d10' 
  AND token = 'HrIZmLDV22YsSdnW3ppbHeEA/a79428Ath9aXdom/xA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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