SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf1a59cb51f4395c1accb15f46757cc23e9eb68f4a069e52b13ae79891188da5' 
  AND token = 'gkFGd/xEsKdq/T2Ecu8nwHomDZ+ZErvfIxMLKPI6C0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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