SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a087b99a58a0bbff3643127c162cf4b4605345e8aa590a40948cbe73170dc0d' 
  AND token = 'DpZqnDh55A5KSVdHDArkgzdKi0C/WJxOZKjUjOAwzSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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