SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecddce1773d81492f97fca13eca9ddbccb0862ea112f3183842be3ef26f32bbf' 
  AND token = 'YW3YXGz16GnsONiukRnQDBiUNkXEhzmvgleMJ/BpAwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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