SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9c96e5adecbecf7ca1088acab6257ced65e8963c3a53119170a7714dc771530' 
  AND token = 'YoYN1sgqZ4DKthnh6M0RF+qzrZq5IhtFY3DcUFAthG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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