SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82a0be7397f8f172013be5ec42395ab5ab647f9dbcf20c83c0962a009363ae9c' 
  AND token = 'wXRCryWTncDJXSY59Az6G/V+EsSrstMtL2K+d5VRco8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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