SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aadd074435ae18a3f869b9dc893f2d949193be880afef80f8addb0a36ba86f47' 
  AND token = 'zSUOaxPjfZd3yh6t8/ZOjDEEjhmz9SUaUemET3EjaTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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