SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a74e5c6999d44f0cafb7765ad03ed2ed57c8297542bfb60a08209ef4b153eed' 
  AND token = 'XRgxbqSPaEM77SLUMMAU7kCeYcFbPhU7YER2MCVle6k=' 
  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"
    }
  }
}