SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb522268349aba51bcaf531e63aaa5391d68aaf1847d51b6345c3ec4a0788cf6' 
  AND token = '19F1nS7rTaTgkdRVhh8jhCeQNGaMqLztrbIvUPd3K4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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