SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5b2d111edfad31b0c25f5f73bb75af87072258ae73ac59e45e8c0b7959ce766' 
  AND token = '4CRAJVdQC8xVWDk99Ur5eLqgI+VFezgujKf+2/XgXOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}