SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92f57644107b95091c3f1060b560ed43af4db34175992e7bc4fc1353c6bfd037' 
  AND token = 'hBliSwCEbQjnPhnu6cb+AxNwguznnsmjfPxEwfUgmKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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