SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22bc0bd73106e5fe0a7c96b58d515be871a73e9ab8231be30d54b221198f0b7c' 
  AND token = 'CkjawF6toRpFeZQJgntHCVew5qdWyCRpUP7Nh3fGUxQ=' 
  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"
    }
  }
}