SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5776e1ce2f87817888dc9b5623b39147a3a4eb195be2647ac0b24cb557ddc2a9' 
  AND token = 'JxIxtmmqgpGm3lAqqHiU3BqdsvITyqbVtLVg6GkG040=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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