SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '061412c20fabcd2d1a42d24a75ad34b26a76a608119f7a0c1396060dfaf3407a' 
  AND token = 'WmEb/ZJlX6M31MP4dc39o7BJDU5Db+KfVkW8oiXmycE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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