SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cb73a76d22a4993f5a09bcf0009b59bf81e7745fee55cd06f8188d292c1b6d4' 
  AND token = '74sL7vT+Yd/xngbvb4jUQvZjDrQKshaqb4SCtWg1OkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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