SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e862ddff3b0c0b29785b5025702226532776a35633fb3e6d9fd386e31879fbc6' 
  AND token = 'H6K227mw9s+PTwS1B+o73MNu50lqCPKUkb+5qV0nbgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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