SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08a1e431489a214be24ec67b9322e73fbfe41d9765f57be97998f15183306a32' 
  AND token = 'gsAXicGoeDuYHPHmGxo7DEJoRPbo69+fOTTlJ9cPiyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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