SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '773785f0bf34eb0d468cd076bce308449ff94e7599583dbf9135dcd8b9c6b4f6' 
  AND token = 'rVqKWn+sougxOYgcKT6OY1Hj6OvuVMouj3PUD/Fws4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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