SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b61e141425546d4496da164004148cfc40faba4f24b7fcabe730f0559b073327' 
  AND token = 'ZzXtGsSmvOxNeGH7/5RqxhCGrjJ4R2l0zIcoKOsAerk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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