SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7785e596ed9c97b8c31bc0335214760123d45b5b776e3c4eb8bed71ddb70cdcd' 
  AND token = '46nyl7SYNGE+i0U2fPXQyFXVsetaTgwMUsgJYWDqohc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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