SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdbad601d74cfd730f3c507de02d0824ebaf0dfffdae865fbea32acdb4a7356b' 
  AND token = 'mcnTlEJU95c6oG+t2v+9A0i69FKpbO94VVSkv268RWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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