SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11b232699b48352c1fff9da3ccc50cde5d5570679a6668f4d9c4ddd398a3c74b' 
  AND token = 'pMQ/rst4GFFrkrlUgAEtO6xpXQYdLLUlS9l88ppzgEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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