SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e19123f60244b3b5a689fcc446ca3aea7ebc2001f7f5b2bac87fb51da7849c5' 
  AND token = 'sv0MhRlt/Jg1ohRLWuBXjLpTmSXg2mSrLZSSLeqO8Jw=' 
  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"
    }
  }
}