SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89c933650667def4fa6b7fe7e061c9e2bc758d38f4a282bc04aadd76609921d2' 
  AND token = 'C9BsF/jdpSItLaayIKidOVjkYNeo+LL5wLyIo46edq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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