SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e50d520eb578e174b60afb8f1260d41129b1c6a8dd0072ffc980b9264cb449f1' 
  AND token = 'Lj5ygrutrKqpSJkm5DFuC3FtpX/5lhwpk/k3HuV9lFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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