SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '655680c827572ee97448d5461a8793a98c5673ac1858f5ce549c1a26de0ed53f' 
  AND token = 'gRbUs9mwBBLBo23qd8/6CHUUCIzJLXQYOk8pojBLmVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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