SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4b7bfbc6aed46c45a6005b8abd6959306d0035868f4921784de1020e213c0f1' 
  AND token = 'ALTvslQchIBv+yoCI7t2gXbwMYNAV78pNlvMfgZQQfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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