SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1f75d02648f176b97f16760254a58c5483144ac70bed4f2f64bd8063bd8ca7d' 
  AND token = '/zgKki0DEfXEttBmYr6tPkTeyMTuflllhYzBuPJCNpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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