SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa902e33686716533c18141bf4d74373c6f26591045385426f8ff9f3dbd8342b' 
  AND token = 'vsgWLTt9iehyvXkrfeuzAKjkj4B8xdFmUhc2Bk/Va84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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