SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '759f9646199503ba0b99134229f77efcc9bfdbf0fdb3f9f33eaaba5b5dfef62f' 
  AND token = 'WkozQLTnO9nEmkuH+WpsN4jvrDFB++dlqExdccPs64E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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