SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '683c7ef102e64c785819aca4a79bac82e1e14ed20a2acf6b335d636836665c3a' 
  AND token = 'Mm7O2ZQBmW/ClKGtjNwDuP6JLDmBsJULsC6qKvqEV08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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