SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a67e5a181750284969b7d4ba7c0769c666e1a00c56bd915b8dc84148319ae728' 
  AND token = 'LHYXHb5hRPjhqMqv6V0Gtvlz3+MsR7g8vJ7OMHGSpP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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