SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d6495b924cf1e52b2ac9da999f9833177f5eeef3017e33da3630cf38a956581' 
  AND token = 'xq2kJjqqyJCh9lu/M+lEM7c/wB6zsDv42UkEE1joFiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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