SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c140fcfbbb57941fcbd27358ec11d8764d37f88e18e6f966cff02b919bae168b' 
  AND token = 'RMZPnvEjVECQR/FGqH5P0FhD/7rJLFM6mBw9kCk/b8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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