SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9ef81337711e0698d79151b7ae1131b0db8b314ba8d38d38662ab931055fde8' 
  AND token = 'dJfqqe11OzrU0R+1XLF2ojxMv+33hEvYkZ3up8pBGIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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